A simple Swift library for JSON-RPC

Features:

• type-safety
• flexible data transport support
• concurrency support

Integration

dependencies: [
    .package(url: "https://github.com/ChimeHQ/JSONRPC", from: "0.9.0")
]

Usage

The core type you'll use is JSONRPCSession. It requires you set up a DataChannel object that handles reading and writing raw data.

let channel = DataChannel(...)
let session = JSONRPCSession(channel: channel)

let params = "hello" // any Encodable
let response: Decodable = try await session.sendRequest(params, method: "my_method")

Task {
    for await event in await session.eventSequence {
        switch event {
        case .request(let request, let handler, let data):
            // inspect request, possibly re-decode with more specific type,
            // and reply using the handler

        case .notification(let notification, let data):
            // inspect notification
        case .error(let error):
            print("Error: \(error)")
        }
    }
}

DataChannel

The closures on the DataChannel allow different transport mechanisms to be used. The JSONRPC package provides a few basic variants:

• Predefined messages channel
  • A channel that delivers a static set of messages
  • Usage: let channel = await DataChannel.predefinedMessagesChannel(with: messages)
• Stdio channel
  • Using stdout + stdin as message transport.
  • Note: When using this transport, make sure no non-protocol messages are sent to stdout, eg using print
  • Usage: let channel = DataChannel.stdioPipe()
• Actor channel
  • Using swift actors to pass messages.
  • Can eg be useful for testing, where both client and server are implemented in swift and running in the same process.
  • Usage: let (clientChannel, serverChannel) = DataChannel.withDataActor()
• WebSocket channel
  • Uses URLSessionWebSocketTask as a message transport.
  • Usage: let channel = DataChannel.webSocket(url: socketURL, terminationHandler: { print("socket closed" })

Contributing and Collaboration

I would love to hear from you! Issues or pull requests work great. Both a Matrix space and Discord are available for live help, but I have a strong bias towards answering in the form of documentation. You can also find me on mastodon.

I prefer collaboration, and would love to find ways to work together if you have a similar project.

I prefer indentation with tabs for improved accessibility. But, I'd rather you use the system you want and make a PR than hesitate because of whitespace.

By participating in this project you agree to abide by the Contributor Code of Conduct.